Process for producing a. fuel from pulverized coal



Patented Nov. 27, 1928.

UNITED STATES PATENT OFFICE.-

WALTER EDWIN TRENT, OF NEW YORK, N. Y., ASSIGNOR TO TRENT PROCESS CORPO-RATION, OF NEW YORK, N. Y., 'A CORPORATION 01' DELAWARE.

PROCESS FOR PRODUCING A- FUEL FROM PULVERIZED COAL.

No Drawing.

The invention relates to improvements in a process for producing a fuelfrom pulverized coal having the characteristics of vaporized liquidhydrocarbon and the product resulting from such process.

It is an object of this invention to provide a process by which finelypulverized coal is treated so that the fuel particles will be entrainedand carried by vapors and gases,

generated from the coal particles.

I have discovered that if coal containing a desired volatile content isreduced to an extreme degree of fineness and then heated to a.temperature preferably in excess of 200 C., that vapors and gases aregenerated in suflicient quantity to freely carry the fine carbonarticles in suspension therein so that the fuel while produced entirelyfrom coal has the desirable characteristics of a liquid hydrocarbon andcan be used in fields where heretofore it has been practicallyuniversally the custom to employ liquid oils. The heat treatment of thisexcessively fine coal apparently has the effect of rendering the coalparticles themselves so mobile that the generated gases entertain nodifiiculty in carrying such particles in suspension therein to a pointof storage or consumption.

The fuel product produced by this process consists essentially of gasesgenerated from finely pulverized coal with the said partially carbonizedcoal articles thoroughly distributed and entramed in such gases forminga free flowing fuel that may be mixed with the desired quantities of airto provide an explosive combustible mixture for use in internalcombustion engines and elsewhere.

In carrying out my process I find that it is essential to reduce thecoal to an exceedingly fine state of subdivision. The coal should bepreferably reduced toafineness in excess of 300 meshes or in such animpalpable state that a substantial part of it is capable of beingmeasured in microns. The coal selected should have a high volatilecontent. Any of the high volatile coals can be used, but as anillustration I may use a bituminous coal having a volatile content inexcess of 25 per cent.

As the product roduced by this process is highly desirable or use in aninternal com bustion engine, I referably remove from the coal itsnon-car onaceous matter such as silica, etc. To effect the separationpfthe carbon from the non-carbonaceous content of the coal the saine ispreferably subjected to Application filed November 22, 1926. Serial No.150,153.

the purifying treatment described in my Patents 1,429,163 and 1,429,164,although it will be apparent that if the coal selected is substantiallyfree of ash no purifying treatment need be resorted to.

The very fine coal with or without purification is then introduced to avessel or treating zone of any suitable character. \Vhen in such zonethe coal is heated to a temperature of 200 (1., or over by a heatingflame which will cause the coal to-rapidly attain this temperature. Ihave discovered that when rapidly heated to or above this temperaturethe coal particles assume a condition resembling that reaction whichoccurs during the boiling of water. Multitudes of gaseous bubbles areevolved, which carry away in suspension the very fine partiallycarbonized carbon particles. In fact, the material might becharacterized a flowing one, inasmuch as the gases and the entrained orcontained fuel particles are very mobile and can with ease be conductedto a carburetor, a burner or a source of storage.

As an example, a bituminous coal having a volatile content in excess of25% isreduced to a fineness such that all particles thereof will pass ascreen having 300 meshes per linear inch. The thus reduced coal, with orwithout a purification treatment for the removal of ash andnon-carbonaceous constituents according to the processes described in myPatents No. 1,429,163 and No. 1,429,164 above mentioned, is then rapidlyheated to a temperature of at least 200 C. Preferably the coal iscontinuously fed to the heated zone and the evolved vapors and thecarbonaceous particles entrained therein are led from the zonesubstantially as fast as formed. It is also desirable to substantiallyexclude air from the heating zone and also to prevent the interminglingof air with the gaseous fuel thus produced during the period While suchfuel is being transported to the point where it is to be consumed.

Upon observation it appears that during this heat treatment the evolvedgases often take a darkened appearance which clearly indicates that thepartially carbonized particles are entrained therein and are beingcarried along by the energy of the gases.

It will be understood that to produce this fuel product the coal must beexcessively fine in its state of sub-division, and that it must containa substantial volatile content. While for use in explosive engines or itmay be used for any other purpose where an explosive charge is needed orwhere a gaseous fuel for combustlon 1s deslred.

The finely pulverized coal may further more, if desired, be amalgamatedor placed in suspension with a liquid hydrocarbon oil so that when theoil is vaporized the necessary gases will be supplied to carry the fineparticles in suspension. Such an operation would be resorted toparticularly at times when a coal is being used which is low in volatilecontent.

, Having thus described my invention, what I claim is:

1. A process for producing a fuel, consisting in pulverizing coalcontaining a substantial volatile content to a fine state of division,and in heating such material to remove volatiles therefrom in sufficientquantity to en-.

train and carry in suspension therein the fine carbonaceous particles.

2. A process for producing a flowing fuel consisting in pulverizing coalcontaining a volatile content not substantially lower than 25 per centto a fineness of at least substantially 300 meshes per linear inch, inheating such coal to a temperature of at least 200 C;, to removevolatiles in suflicient quantities to entrain and carry in suspensionthecontained finely divided carbonaceous particles.

3. A rocess for producing a fuel consist- III in finely pulverizing coalcontaining a su stantialvolatile content, in heating such coal to removevolatiles in sufiicient quantities to entrain and carry in suspensiontherein the finely divided carbonaceous particles.

4. A process for producing a fuel consisting in finely pulverized coalcontaining a substantial volatile content, in heating such coal toremove volatiles in sufiicient quantities to entrain and carry insuspension therein the finely divided carbonaceous particles, saidparticles being sufiieiently fine and the volatile content removed fromthe coal being sufficiently great to cause such volatile content tofreely carry the distributed carbonaceous particles.

5. A process for producing a fuel consist- 1 o in finely pulverizingcoal containing a su stantial volatile content, in removing carbonaceousfrom non-carbonaceous matter contained in said coal, and in thereafterheating the finely divided carbonaceous material to a temperaturesufiicient to remove volatiles therefrom in a quantity capable ofentraining and carrying in suspension the finely divided carbonaceousfuel particles.

6. A process for manufacturing a fuel consisting in reducing coalcontaining a substantial volatile content to a degree of fineness inexcess of 300 meshes per linear inch, in thereafter heating said finelyreduced particles to a temperature to remove volatiles therefrom in aquantity sufiicient to entrain and carry in suspension therein thefinely reduced carbonaceous particles.

7. A flowing fuel composed of gases evolved from finely pulverized coal,with the carbonaceous particles of said coal distributed throughout andcarried in suspension in said gases.

8. A fuel composed of gases evolved from finely pulverized coal with thepartially carbonized particles distributed within and suspended In saidgases to flow therewith.

9. A flowing fuel composed of volatile gases and finely pulverizedcarbonaceous particles distributed in and suspended by said gases.

10. A fuel composed of gases evolved from finely divided bituminous coalhaving suspended an'd entrained therein the partially carbonized coalparticles.

In testimony whereof I afiix my signature.

WALTER EDWIN TRENT.

